Willful Murder (Ken Kumai, 1981)

The president of the Japanese National Railways is found dead during a period in which train service is plagued by numerous layoffs, strikes and shutdowns. The government says that the president was murdered; the police claim it was a suicide. A quizzical reporter follows the case for years, but the basic question remains unanswered: was the victim killed by members of the burgeoning Communist movement in Japan, or was the death stage-managed by the authorities in hopes of discrediting the Communists? 

Original title: Nihon no atsui hibi bôsatsu: Shimoyama jiken

Director
Kei Kumai
Writers
Kimio Yada, Ryûzô Kikushima
Stars
Tatsuya Nakadai, Ichirô Nakatani, Yôko Asaji

Subs: English
YouTube link: https://youtu.be/iksiIZ0NAt4